1. The present invention relates to a pattern-forming method, and more particularly, to a method of selectively forming a pattern on a substrate utilizing a photo-induced reaction.
2. Description of the Prior Art
Presently, the pattern used for manufacturing a semiconductor element is formed exclusively by a photoetching process (PEP). The process comprises the steps of coating a substrate with a photoresist, exposing the coated substrate to light, and developing a resist pattern. In the case of processing a semiconductor surface, a resist pattern formed by PEP is used as a mask for etching the semiconductor surface so as to transfer the pattern of the mask onto the semiconductor surface. However, the pattern-forming technique utilizing PEP requires many steps, making it expensive in terms of manufacturing.
Recently, proposed are a resist pattern-forming technique and an etching technique utilizing a photo-induced reaction. The techniques permit omitting the conventional PEP, leading to a marked reduction in the number of steps and, thus, to lower manufacturing costs. For example, a material is selectively deposited on a semiconductor substrate by utilizing a photochemical reaction. The surface of the semiconductor substrate is processed with the deposited material layer used as a mask. The particular technique permits omitting 3 to 4 steps, compared with the conventional technique utilizing PEP. Also, it suffices to employ a single etching step on the semiconductor substrate, when a photo-induced reaction is utilized.
However, the pattern-forming technique utilizing a photo-induced reaction is defective in that, in forming a fine pattern, the pattern may become blurred by, for example, the diffraction of light, resulting in a failure to produce a sharp pattern.